Motor-driven tooth brush



Nov. 30, 1965 Q DAYTON ETAL 3,220,039

MOTOR-DRIVEN TOOTH BRUSH Filed July 30, 1963 2 Sheets-Sheet l INVENTORS CHARLES A. DAYT N BY DONN D. DAN\E\.SON

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ATTQRDEYS Nov. 30, 1965 c. A. DAYTON ETAL 3,220,039

MOTOR-DRIVEN TOOTH BRUSH Filed July so, 1963 2 Sheets-Sheet 2 FIG. 5 FIG. 6

JNVENTORS -muss A. DAYTON BY DONN D. DAMELSON mmw m ATTORMEYS United States Patent 3,220,039 MOTOR-DRIVEN TOOTH BRUSH Charles A. Dayton, 1987 N. Broad St., Galesburg, Ill., and

Donn D. Danielson, Oak Lawn, lll.; said Danielson assignor to said Dayton Filed July 30, 1963, Ser. No. 299,143 3 Claims. (Cl. l28) This invention relates to a motor-driven tooth brush. It is more specifically concerned with an electricallypowered tooth brush that employs a circular brushing action.

In order to facilitate dental hygiene, a variety of prophylactic equipment has been made available to minimize the manipulative effort involved in the hand-brushing of teeth by the layman. Accordingly, some motordriven tooth brushes have become generally accepted by dentists and the layman as an effective means for the brushing of teeth. To minimize the reluctance of the average layman to accept new or alternative procedures, these motor-driven appliances have adapted the mode of brushing teeth which has been generally employed for a number of years, namely, the use of a conventional tooth brush. Various actions have been provided by the power unit to impart oscillatory, reciprocating, rotary or other motions to the tooth brush head. Considerable research has been done by motor-driven tooth brush manufacturers in investigating the efficacy of these particular motions. In no instance, however, has there been made available a motor-driven tooth brush which uses the timeand result-proven technique employed by dentists for effecting the cleaning of teeth, namely, the circular cleaning action imparted by a revolving cleaning element.

The circular method for cleaning the teeth is far superior to any of the brushing techniques which have been developed for use with the conventional tooth brush head. The circular action not only provides a therapeutic effect for the gum tissue by virtue of the gentle massage effect, but also produces other beneficial effects which result in the teeth not only being brushed, but also being cleansed by removal of surface stain to improve the cleaning of the teeth and give them their natural white appearance. Although tooth brushes with a circular cleansing effect have been employed by the prior art, the various approaches which have been utilized by the prior art devices have, in general, precluded their use as a portable device which can be readily manipulated by the average person. Furthermore, the prior art devices have not been provided with readily removable heads which, for sanitary purposes, are desirable in order to permit each individual who uses the tooth brush to have his or her own personal cleaning instrument.

According to this invention, however, there is provided a motor-driven tooth brush which utilizes a circular action for cleaning purposes and which is provided with a removable head, readily detachable from the power unit, in order to permit the interchanging of separate heads for individual use.

Referring to the drawings:

FIGURE 1 is a view of the illustrative embodiment of the motor-driven tooth brush of this invention, wherein the power unit is self-contained;

FIGURE 2 is an enlarged, cross-sectional view taken along line 2-2 of FIGURE 1, illustrating the catch plate mounted on the removable cleaning unit of the tooth brush of this invention to permit the interchangeability of cleaning units;

FIGURE 3 is a cross-sectional view taken along line 33 of FIGURE 1, illustrating the arcuate tines mounted on the power unit, which removably engage 2 with the catch plate shown in FIGURE 2 to permit the attachment of the cleaning unit to the power unit;

FIGURE 4 is a longitudinal cross-sectional view taken along line 44 of FIGURE 1, illustrating the interior arrangement of a tooth brush of this invention;

FIGURE 5 is an enlarged, longitudinal, fragmentary cross-sectional view taken along line 5-5 of FIGURE 2 of the end of the removable cleaning unit which is attached to the power unit;

FIGURE 6 is an enlarged, longitudinal, fragmentary cross-sectional view taken along line 6-6 of FIGURE 3 of the attachment means employed on the power unit; and,

FIGURE 7 is an enlarged, sectional, fragmentary view of a portion of the embodiment illustrated in FIGURE 4.

In the drawings there is illustrated an illustrative embodiment of the motor-driven tooth brush of this invention. Referring to FIGURE 1, it will be seen that the tooth brush of this invention consists of -a self-contained power unit 10 having removably attached thereto in axial alignment a cleaning unit 11, which is driven by power unit 10. As seen in FIGURE 4, the illustrated power unit 10 consists of tubular housing which encloses an electric motor 16 and a rechargeable battery 17. An offon slide switch 18 is employed to control the operation of the unit. The motor 16, battery 17 and switch 18 are connected in series, with the negative pole of battery 17 being connected to the motor 16 by means of springed lead 24, the positive pole of battery 17 being connected to the motor 16 through switch 18 and the switch leads 18A and 1813, which are closed by the sliding action of switch 18. The components of the power unit are conventional and any suitable motor, battery, switch arrangement or housing design can be employed in providing the power unit for driving the cleaning unit 11.

In the illustrated embodiment, the end portions of housing 15 are provided with flanged ends 19 and 20, which are engirded with metallic rings 21 and 22 which are used to connect the power unit to a suitable charging unit (not shown) for recharging battery 17. The negative charging connector ring 21 is connected directly to motor 16 and lead 23 is used to connect the battery to the positive charging connector ring 22. The power unit charging circuit is completed through springed lead 24, which electrically connects the battery 17 to the motor 16.

A removable cap 25 is employed to enclose the open end of one end of tubular housing 15. The other end of housing 15 is similarly enclosed 'by a cover plate 26, which is provided with a central opening through which extends drive shaft 27 of motor 16. Attached to drive shaft 27 and extending outwardly beyond the face of cover plate 26 is the drive element 28 of coupling means 28, which is employed to supply power to the cleaning unit 11. Although the power unit 10 is shown to consist of a particular arrangement of units, there are other arrangements which can be utilized, which will permit the use of a self-contained power unit to provide a suitable drive means for operating the cleaning unit 11 of this invention.

The cleaning unit 11, which is employed in the illustrated circular tooth brush, consists of a flanged end portion 30 at the end which is attached to the power unit 10. At the work piece end 31 of the cleaning unit 11, a removable cleaning means, such as brush 32 or other suitable cleaning element, is provided. An elongated shank portion 33, having a cross-sectional area substantially less than the cross-section of the power unit 10, is employed to connect the flanged end portion 30 to the work pieme end 31 of the cleaning unit 11. The dimensions of the shank portion 33 and the work piece end 31 are selected to facilitate the manipulation of the work piece end 31 in the oral cavity, especially in the upper and lower buccal area, during use, and to simulate the manipulative efifect provided by a conventional tooth brush. A suita'ble driven means is located in the cleaning unit 11, such that a circular motion is provided to the brush 32, as illustrated. A driven shaft 34 is coaxially mounted within a longitudinal passageway 35 provided in the shank portion 33. One end of the driven shaft 34 is connected to the driven element 28 of the coupler 28 which connects the driven shaft 34 to the drive shaft 27. The driven shaft 34 is provided with suitable bearings 36, if necssary, which maintain the alignment of the driven shaft 34. Mounted on the other end of the driven shaft 34 is a bevel gear 37. Bevel gear 37 cooperates with bevel gear 38 mounted on the work piece shaft 39. One end of work piece shaft 39 is journalled in a suitable thrust bearing provided in the work piece end 31 of cleaning unit 11. The other end of work piece shaft 39 is journalled in an opening provided in the face of head portion 31. Chuck means are provided in the free end of work piece shaft 39 which permit the detachable connection of a cleaning element such as brush 32 with work piece shaft 39. In one form of a chuck, the cleaning element, such as brush 32, is provided with a threaded shank (not shown) which is used to connect the brush 32 to a thread hole (not shown) provided in work piece shaft 39,. In selecting the hand of the thread which is employed, it should be noted that preferably a left-handed or right-handed thread should be employed, depending upon the direction of rotation, and the thread hand employed should be one which does not become loosened by reason of the engagement of the brush 32 or other cleaning elements on the tooth surface.

To permit the removable connection of the head of the cleaning unit 11 to the power unit 10, a suitable attachment means must be provided whichwill permit the coupling element 28 of the power and cleaning units to interconnect and also retain the cleaning unit 11 in a rigid, fixed position on the body of the power unit 10. A number of suitable attachment means can be employed. In the illustrative embodiment, one end portion of power unit housing is fitted with an integral annular ring 40, which projects outwardly from the face of cover plate 26. The outer diameter of the annular ring 40 is less than the outer diameter of the flanged end 19, such that a shoulder 41 is formed on the outer face of cover plate 25. In the flared, flanged end portion 30 .of the cleaning unit 11, a circular recess 42 is formed with the dimensions of the circular recess 42 being such as to permit the end portion 30 of cleaning unit 11 to fit onto the shoulder portion 41 of the power unit 10. The power unit 10 and the cleaning unit 11 are held in a fixed position by means of a suitable attachment mechanism which retains the power unit and the cleaning unit 11 in a desired relationship during use.

One such attachment mechanism which can be employed consists of the illustrated interlocking finger arrangement, which comprises mounting a trifurcated catch plate 43 on the inner face 42, attached thereto by means of threaded fasteners 44. The trifurcated catch plate 43 consists of a web member 45, from which has been struck a plurality of fingers 46 angularly displaced each to the other an equal distance and radially extending from said web member. One end of the fingers 46 is attached to the web member 45 and the fingers 46 are so shaped that the free ends of the fingers 46 extend away from the plane of the web member 45. The other cooperating portion of the attachment means is secured to the cover plate 26 of the power unit 10 by means of fasteners 48. This portion of the attachment means consists of a base member 49 attached to the cover plate 26. Extending from the base member 49 are a plurality of equally spaced arcuate tines 50 which. engage the underside finger portions 46 of the trifurcated catch plate 43 upon rotation of one or the other elements in a direction such that the tines 50 are relatively rotated into a position such that the arcuate tines 5d. are moved transversely under the fingers 46 of trifurcated catch plate 43.

The materials of construction employed in fabricating the trifurcatcd catch plate 43 and the arcuate tines 50 are selected so that a springed action is provided, whereby, through the interaction of. the fingers 46 and the arcuate tines 50, the removable head is biased into a rigid position upon the shoulder 41 of the power unit 10.

In bringing the removable cleaning unit 11 into fixed engagement with the power unit 10, the tongue portion 51 of driver coupler means 28 engages with the groove 52 formed in the driven coupler element 28", whereupon engagement of the power unit is adapted to drive the driven elements of the removable cleaning unit 11. Although a three finger-three tine assembly has been described, two finger-two tine or other assemblies can be used.

In addition to the attachment means formounting the removable cleaning unit 11 on the power unit 10, described above, other attachment means can be employed. For example, a bayonet type connection employing a pin and slot connection, an attachment means whereby one unit is threadedly attached to the other unit, attachment means employing hinged clips or the like for connecting the respective units, attachment means employing magnetic forces provided. by permanent magnets embedded in the cooperating cover plates of the respective units, or other suitable attachment means can be provided for removably attaching the cleaning unit 11 to the power unit 10. The attachment means used must not permit any relative movement'of the units each to the other during use, and must provide a rigid, integrating relationship between the units.

Couplings other than the tongue and groove type described above can also be utilized. Alternative couplers include serrated face plates wherein the grooves of the drive face plate will engage with the lands of a corresponding driven plate, a coupling employing a splined drive shaft Which fits into a grooved, .internal cylinder member provided on the cleaning unit 11, rubber-faced clutch plates and other suitable ,expedients can also be utilized. If desired, the drive and driven coupling elements can be biased into engagement by suitable springloading or the like.

Similarly, alternative chuck arrangements can be employed for mounting the cleaning element on the work piece shaft 39. Preferably, the chuck end of the work piece shaft 39 is provided with means whereby the cleaning element is frictionally and removably engaged with the work piece shaft chuck, such as threadedly attaching the cleaning element to the shaft or other simpler arrangements involving the insertion and frictional engagement of a shank element in a suitable hole.

In selecting the cleaning element, which is to be employed to impart the circular cleaning action provided by the tooth brush of this invention, a relatively soft bristled brush having a diameter of about is preferred in order to cover a sufficient amount of tooth area during the cleaning operation. In this regard, if it is desirable to increase the area of coverage for cleaning purposes, at least two cleaning elements could be gauged in alignment by suitable gearing and a suitable extension of the work piece end of the cleaning unit 11, to provide either concurrent or countercurrent rotation of the cleaning element. Smaller brush diameters, such as those used professionally by dentists in their cleaning procedures, can also be used, although the cleaning time takes longer when used by a layman. Other cleaning elements, such as rubber cups, combination rubber cups and bristle brushes and the like can also be used where a more rigor ous cleaning action and/or gum massaging eifect is desired. Conventional dentifn'ces can be employed as the cleaning aid for use in conjunction with the circular cleaning effect provided by the cleaning elements desired.

In selecting the components for a self-contained battery-operated power unit, a DC. motor should be employed, such as to give a torque of about 1 to 3 inchounces, and a range of speeds from about 3,000 to 5,000 revolutions per minute, although a motor having operating characteristics outside these ranges can be used. In order that the power unit can be self-contained, it is preferable that the motor selected be battery-driven, using either rechargeable batteries or mercury-alkaline batteries of the throw-away type. Where the use of an electrical line cord connected directly to a source of power, such as 110 volt A.C., is suitable or can be employed, an alternating current motor can be utilized with suitable provisions made for use of a power line cord to connect the power unit with a suitable source of power, such as a convenience outlet. It is preferred, however, that a DO, battery-driven motor be employed in order to avoid the inconvenience resulting from the use of a power line cord for supplying power to an alternating current motor. Where a battery is utilized, a small voltage, such as about 1.25 volts, can be used, whereas the use of an alternating current motor requires normal line voltages of 110 volts. Where a rechargeable battery is employed, it is necessary to provide, as auxiliary equipment, a suitable charging unt which will permit the recharging of the power unit.

It is evident from the foregoing description of the illustrative embodiment of this invention that various modifications can be employed by those skilled in the art to which this invention pertains. Accordingly, it is intended that the instant invention be limited only in the manner described by the appended claims.

What is claimed is:

1. In a motor-driven toothbrush, a self-contained power unit comprising a tubular casing, a battery positioned within said casing, a motor having a drive shaft positioned within said casing, manual means located on the outer wall of said casing for selectively connecting said motor to said battery to actuate said motor causing rotation of said drive shaft, a cleaning unit comprising an attachment end, a work piece end and an elongated rigid shank portion having a cross section substantially less than the cross section of said power unit, a terminal end of one of said units being provided with a peripheral shoulder, a terminal end of the other of said units being provided with a circular recess adapted to frictionally receive and engage said shoulder, a work piece shaft rotatably mounted in said work piece end on an axis transverse to the longitudinal axis of the shank portion, said shaft having a chuck means for frictionally and removably holding a tooth cleaning element, driven means for driving said work piece shaft, coupling means for removably coupling said drive shaft and said driven means, and attachment means for removably attaching said cleaning unit to, and in coextensive alignment with said power unit, said attachment means comprising a multifurcated catch plate having a central web member and a plurality of raised fingers extending radially from said web member with equal angular spacing, said catch plate being secured to a terminal end of one of said units, a plurality of raised, arcuate tines corresponding to said fingers circularly disposed about the center of one terminal end of the other unit and spatially oriented on said terminal end in relationship to said fingers whereby the relative rotation of one unit about its longitudinal axis will permit the engagement of said fingers and tines with said tines transversely engaging the underside of said fingers.

2. A motor-driven toothbrush which comprises a selfcontained power unit having a motor-driven drive shaft, a cleaning unit comprising an attachment end, a work piece end and an elongated rigid shank portion having a cross section substantially less than the cross section of said power unit, said shank portion having a bore throughout its length and along its longitudinal axis, a bearing positioned within said shank portion, a terminal end of one of said units being provided with a peripheral shoulder, a terminal end of the other of said units being provided with a circular recess adapted to frictionally receive and engage said shoulder, a work piece shaft rotatably mounted in said work piece end on an axis transverse to the longitudinal axis of the shank portion, said shaft having a chuck means for frictionally and removably holding a tooth cleaning element, driven means for driving said work piece shaft, said driven means comprising a connecting shafthaving a diameter smaller than the diameter of said bore, said connecting shaft being maintained within said bearing to prevent substantial contact between said shank portion and connecting shaft, coupling means for removably coupling said drive shaft and said driven means, and attachment means for removably attaching said cleaning unit to, and in coextensive alignment with said power unit, said attachment means comprising a multifurcated catch plate having a central web member and a plurality of raised fingers extending radially from said web member with equal angular spacing, said catch plate being secured to a terminal end of one of said units, a plurality of raised, arcuate tines corresponding to said fingers circularly disposed about the center of one terminal end of the other unit and spatially oriented on said terminal end in relationship to said fingers whereby the relative rotation of one unit about its longitudinal axis will permit the engagement of said fingers and tines with said tines transversely engaging the underside of said fingers.

3. A motor-driven toothbrush according to claim 2 wherein said toothbrush further includes a thrust bearing located in said work piece end at the end of said work piece shaft opposed to said brush end.

References Cited by the Examiner UNITED STATES PATENTS 368,457 8/1887 Clark 1523 X 1,495,732 5/1924 Gibb 1528 1,869,179 7/1932 Yutzler et al 1549 1,981,688 11/1934 Conti 1528 2,140,307 12/ 1938 Belaschk et al 15-28 2,278,095 3/1942 Rogers 1528 2,808,602 10/1957 Gregoire 15--28 3,005,141 10/1961 Emmons 3202 3,012,263 12/1961 Miller 1528 3,027,507 3/1962 Hubner 3202 3,033,197 5/ 1962 Barckley. 3,089,071 5/ 1963 Hartwig 3202 3,106,732 10/1963 Dayton et a1 l528 FOREIGN PATENTS 477,799 1/1938 Great Britain. 274,374 6/1951 Switzerland.

CHARLES A. WILLMUTH, Primary Examiner, 

1. IN A MOTOR-DRIVEN TOOTHBRUSH, A SELF-CONTAINED POWER UNIT COMPRISING A TUBULAR CASING, A BATTERY POSITIONED WITHIN SAID CASING, A MOTOR HAVING A DRIVE SHAFT POSITIONED WITHIN SAID CASING, MANUAL MEANS LOCATED ON THE OUTER WALL OF SAID CASING FOR SELECTIVELY CONNECTING SAID MOTOR TO SAID BATTERY TO ACTUATE SAID MOTOR CAUSING ROTATION OF SAID DRIVE SHAFT, A CLEANING UNIT COMPRISING AN ATTACHMENT END, A WORK PIECE END AND AN ELONGATED RIGID SHANK PORTION HAVING A CROSS SECTION SUBSTANTIALLY LESS THAN THE CROSS SECTION OF SAID POWER UNIT, A TERMINAL END OF ONE OF SAID UNITS BEING PROVIDED WITH A PERIPHERAL SHOULDER, A TERMINAL END OF THE OTHER OF SAID UNITS BEING PROVIDED WITH A CIRCULAR RECESS ADAPTED TO FRICTIONALLY RECEIVE AND ENGAGE SAID SHOULDER, A WORK PIECE SHAFT ROTATABLY MOUNTED IN SAID WORK PIECE END ON AN AXIS TRANSVERSE TO THE LONGITUDINAL AXIS OF THE SHANK PORTION, SAID SHAFT HAVING A CHUCK MEANS FOR FRICTIONALLY AND REMOVABLY HOLDING A TOOTH CLERANING ELEMENT, DRIVEN MEANS FOR DRIVING SAID WORK PIECE SHAFT, COUPLING MEANS FOR REMOVABLY COUPLING SAID DRIVE SHAFT AND SAID DRIVEN MEANS, AND ATTACHMENT MEANS FOR REMOVABLY ATTACHING SAID CLEANING UNIT TO, AND IN COEXTENSIVE ALIGNMENT WITH SAID POWER UNIT, SAID ATTACHMENT MEANS COMPRISING A MULTIFURCATED CATCH PLATE HAVING A CENTRAL WEB MEMBER AND A PLURALITY OF RAISED FINGERS EXTENDING RADIALLY FROM SAID WEB MEMBER WITH EQUAL ANGULAR SPACING, SAID CATCH PLATE BEING SECURED TO A TERMINAL END OF ONE OF SAID UNITS, A PLURALITY OF RAISED, ARCUATE TINES CORRESPONDING TO SAID FINGERS CIRCULARLY DISPOSED ABOUT THE CENTER OF ONE TERMINAL END OF THE OTHER UNIT AND SPATIALLY ORIENTED ON SAID TERMINAL END IN RELATIONSHIP TO SAID FINGERS WHEREBY THE RELATIVE ROTATION OF ONE UNIT ABOUT ITS LONGITUDINAL AXIS WILL PERMIT THE ENGAGEMENT OF SAID FINGERS, AND TINES WITH SAID TINES TRANSVERSELY ENGAGING THE UNDERSIDE OF SAID FINGERS. 